23/08/05 WASHINGTONReuters) - The highly contagious soybean rust diseasewas found in a sixth Alabama county and could soon spread to other fieldsin the state, the U.S. Agriculture Department said on Tuesday.The fungus was found in a soybean sentinel plot in Autauga County, inthe center of the state and adjacent to ElmoreCounty where rust was found earlier this month.The sample had five infected leaves collected from a soybean plot atthe R6 growth stage. R6 is defined when the podhas green beans inside.Ed Sikora, a plant pathologist at Auburn University, said in a reportposted on the USDA's soybean rust-monitoring Website that the fungus wouldlikely spread to other counties inthe state."Growers in south and central Alabama with fields in early tomid-reproductive stages are at high risk for soybean rust,"said Sikora. "Weather conditions are very conducive to infection from thedisease, especially where frequent/dailyrain showers are occurring."The yield-cutting disease thrives in warm, humid weather with cloudyskies.Separately, the USDA said a cold front and thunderstorms moving slowlythrough the southeastern states could spread soybean rust into new areasthis week. Most vulnerable are states that already have some countiesinfected with the fungus, plus North Carolina and eastern Tennessee, itsaid.Fungicide is recommended for most soybean growers in the state whosecrops are in the reproductive stages. Farmers with crops that have maturedbeyond the R5 growth stage do not needto spray.The windborne disease so far has remained confined to Georgia,Alabama, Mississippi, Florida and South Carolina. The majorsoybean-growing states in the Midwest, where crops are nearing maturity,are no longer believed to be vulnerable to an outbreak of the disease thisyear.Suspicious spores have also been found in several states this yearincluding Kentucky, Tennessee, Louisiana andIllinois, the largest soybean growing state. Last Friday, six spores werediscovered in a trap in Suffolk, Virginia.